The effect of hydrogen treatment (400 A degrees C/1 h) on the catalytic properties toward H2O2 decomposition of iron oxide based materials dispersed over activated carbon were investigated. Two different supports were evaluated: a commercial activated carbon (ACM) and an activated carbon produced from spent coffee grounds (ACR). The catalysts were characterized using XRD, SEM, N-2-sorption, XPS and TPR analysis. The main results suggest the formation of composites with high surface area (> 800 m(2) g(-1)) and the hydrogen treatment resulted in a great increase in the catalytic activity, probably as a function of the reduced iron species (Fe2+ and Fe-0) formed with the treatment. Moreover, the catalyst prepared with ACR showed to be more active than that prepared from ACM.